Selective relay and the like



Dec. 13, 1927.

1,652,199 R E. HALL SELECTIVE RELAY AND THE LIKE Filed Auei. 26. 1924 2 Sheets-She a 1 INVENTOR ATTORNEY Dec. 13, 1927.

. R. E. HALL.

SELECTIVE RELAY AND THE LIKE Filed Au 26. 1924 2 Sheets-Sheet 2 INVENTOR- Rayfiflizll 4431 6 (Z M MAITORNEY Patented Dec. 13, 1927.

UNITED STATES PATENT OFFICE.

RAY EDWIN IIALII, OF VJILMET'IE, ILLINOIS, ASSIGNOR TO HALL RESEARCH CORPO- BATION, A CORPORATION OF DELAWARE.

SELECTIVE RELAY AND THE LIKE.

Application filed. August 26, 1924. Serial No. 734,175

My present invention relates more particularly to selective telegraph receiving instruments and relays of the tuned reed type, in so much asit utilizes the well known principle of causing a relatively feeble alternating current to build up by mechanical resonance, full amplitude vibrations in a v1- brating reed tuned to the frequency of said alternating current while causing little or no response in other instruments on the same circuit because said instruments have their reeds tuned to other frequencies, Thus a number of sets of receiving and transmitting instruments may be operating simultaneously and without. interference because each set employs a different reed tune and alternating current frequency.

One very important novel feature of my present invention is the use of a non-positive medium, preferably a fluid medium and preferably an air jet, whereby the vibrations of the reed are substantially free, yet operate with greatest reliability and effectiveness to control production of a desired indication or a desired effect such as the make and break of a relay circuit. I

While my instruments embodying these novel features, are of. general applicability wherever selective transmission is required, they are of particular advantage on telegraph circuits since by their use new circuits may be secured without stringing new wires; also where the wires already in use are working to normal full capacity, i. e., equipped for quadruplex telegraphy or for multiplex printers, either of which give four circuits, two in each direction. The relay is not designed to take the place of instruments commonly employed, but to supplement them.

It may be applied to such circuits either as a substitute for or in combination with wired wireless, and with the advantage over the latter that the energy does not spill over into other circuits on the same pole line, nor into adjacent telephone circuits, Hence I may have a number of circuits on the same pole line, each using the same sets of, frequencies, whereas wired wireless permits only one set of frequencies per pole line.

The relay preferably includes an electromagnet operated by alternating current and having associated therewith an armature which is carried by a vlbrating reed. The reed has its elasticity and weight (inertia) so adjustedor tuned that proper vibration of the armature cannot be had except when the frequency of the current which energizes the magnet is the same as the natural frequency of vibrationto which the reed is tuned. The reed controls a make and break apparatus for the relay circuit, preferably through an air jet normally impinging with uniform pressure on a yielding member. v

I This air. jet is not of the sound-sensitive type set forth in my Patents Nos. 1,160,072 and 1,3783%. Hence it can be a relatively high pressure jet, of corresponding great power andv certainty of mechanical effectiveness. Under.ordinary condition, the air jet passes through a slot in the upper end of the reed and pneumatically by its pressure normally holds the yielding inember ina displaced position where it maintains a reiav circuit either normally closed or open asmay be desired. Preferably the movable contact member of the relay circuit is mounted upon the movable wall of an expansible chamber such, for instance, as a telescoping cylinder and piston arrangement. 7 Preferably the plston is fixed and the cylinder movable, so that from the jet passing through the piston presses the movable'cylinder rearward. Preferably also, the movement of the cylinderis yieldingly opposed so that if theblast is bafiied the cylinder will return to its normal telescoped position. As the reed is vibrated by the action of the electro-magnet, the slot which is normally in direct alignment with the air blast, will be oscillated across the path of the blast, acting as fiuttering valve to break the force ,of the, jet and thus vary the pressure on the, movable contact member and either opening or closing the relay circuit, as the case may be The purpose of the reed is to vary the effectiveness of the air jet and the. reed may accomplish this purpose by normally battling the jetrwhen stationary and permitting freer flow during vibration, instead of vice versa, as above described. v A preferred. embodimentof the invention includes numerous refinement-s such as means for adjusting the make and brealrcontacts of the relay, means for adjusting-and damping the vibration of the reed and means for adjusting the slot in normal alignment for free passage of the jet. r

A particular advantage of this class of relay is the fact that I am able to use frewith a portion of the insulating casing broken away for the sake of clearness.

Fig. 2 is a view in front elevation thereof.

Fig. 3 is a transverse section on the line 33 of Fig. 2.

Fig. 4: is a view in rear elevation.

Fig. 5 is a sectional detail of the electromagnet on the line 55 of Fig. 3.

Fig. 6 is an enlarged section detail on the line 6-6 of Fig. 2.

Fig. 7 is an enlarged transverse, sectional view on the line T7 of Fig. 2.

Fig. 8 is a detail view of a modification.

Fig. 9 is a wiring diagram.

In the form shown in these drawings, there is an annular open casing or shell 10 of insulating material mounted upon a bracket 11 and within this shell fits the instrument frame comprising a pair of circular plates 13, 13 which may be of metal and spaced apart by rigid frame bars 14;. This frame work may be held within the annular casing member 10 frictionally or in any other coir ventional or appropriate manner, as by screwing one or more of the frame bars 14 to the casing at 1%.

Mounted on one of the plates 13v is a block 15 against which one end of a vibratory reed 17 is firmly clamped by member 16 which is secured by screws 16. An enlarged portion 17 near the clamped end of the reed carries a soft iron armature 18 which is adapted to be attracted by an electromagnet 221, 23 which is of the alternating current type, designed to vary the magnetism effectively in response to fluctuations of the alternating currents and preferably polarized so that each complete alternation of the current will take effect as a single pulsation 01: rise and fall of n'iagnetism without reversal of polarity.

A bolt 18 and nut 18 for securing the arn'iature in place also serve to clamp aweight 19 to the reed, this weight being properly proportioned to the elasticity of the reed so as to tune the reed to the desired frequency of vibration. The magnet may be conveniently mounted upon a U-shaped spring hanger or bracket 20, one end of which is rigidly secured to the. inner face ff disk 13 at 20 and the other end of which maintained against said inner face of e disk by the inherent resiliency of the hanger. A. horse shoe core 21 supported upon the hanger terminates in a pair of upwardly" directed pole pieces 22 encircled by energizing coils 23 extending through an opening 23 in the plate 13, the pole pieces being located in close juxtaposition to the armature carried by the reed. For adjusting the normal gap between the pole pieces of the magnet and the armature, I may employ a screw 24 working through the plate and against a lip 25 at the free end of the U- shaped hanger so that adjusting the screw increases or decreases the gap between the armature and pole pieces.

A twist 26 adjacent the free end of the reed serves to dispose such end in a plane which is at an angle of approximately 90 degrees to the body of the reed. adjacent its free end is formed with a slot 27 normally registering with a nozzle 28 coupled to an air line 29, and discharging air in a thin flat jet. Preferably the nozzle forms the outlet from anair chamber 30 in a block 31 secured upon the plate 13, air being introduced into the chamber from any suitable source through the pipe 29. The air blast from the nozzle 28 normally passes through the slot 27 in the reed and through a similarly shaped inlet 32 in a concave stationary piston member 33 where it applies pressure upon a movable cylinder 34 which is freely slidable over the piston and carrying an axial arm 35 which terminates in one of the contacts 33 for closing the relay circuit. The stationary piston is mounted in The reed an opening 33 in the plate 13 of sufficient size to allow for movement of the cylinder. The piston may be rigidly secured by a screw 33 passed through the block 31 and on which a spacer sleeve 33 is used and also by a screw 33 passed through a block 33 below the plate 13 (Fig. 1). Movement of the cylinder under the pressure of the air jet is opposed by a coiled spring 37 encircling the arm 35 and bearing at one end against the cylinder and at the other end against a block 38 fixed to the plate and through which the arm slides. The relatively stationary contact 39 which cooperates with the movable contact 36 is preferably carried by a screw 4-0 mounted in a block il so that the throw of the cylinder necessary for closing the contacts may be accurately predet rmined. The cylinder is preferably of the very light construct-ion, being preferably a cup of thin aluminum and its fit over the piston can be free enough to substantially avoid friction, since reasonable leakage of air between cylinder and piston is no objection but rather an advantage in that it permits prompt relief of internal pressure and restoration of the cylinder by its spring 37, when the jet is broken up by vibration of the reed.

For limiting the vibratory movement of the reed, I preferably employ an adjustable stop member in the nature of an angular spring arm 12 secured upon the plate and lit) adjustable by a clamping nut 43 working on a screw 44 which is mounted on the plate and extends through an opening in the arm 42. To damp the vibrations of the reed after operating current in the magnet has been cut off, I form an opening 45 in the reed and an aligned opening 46 in plate 13. A rod 4'? extending through the openings is pivotally or loosely connected at 48 to the plate 13" and carries at its free end an adjustable weight 49. This weight'tends to hold the damping rod 47 in frictional contact with the wall of the opening 45 in the reed, with sufficientforce to quickly damp vibration when the actuating current in the magnet has been cut off.

When the alternating currents energizing the magnet are not of the frequency to which the reed 17 is tuned, said reed will remain without substantial vibration in the position indicated in Fig. 6 of the drawings, where the slot in the reed is in direct alignment with the air discharge nozzle 27 and the air inlet 32 through the piston. his is because the individual pulsations of magnetism are too feeble to cause substantial displacement of the reed and successions of such pulsations are even less effective because they are not timed to the natural swing of the reed and what small effect is produced by one pull is interfered with and cancelled by those that follow. In this substantially stationary position indicated in Fig. 6, substantially the full effect of the air jet is transmitted through the piston into the movable cylinder 34. The effect of the pressure thus applied through the relatively small inlet is multiplied many times by taking effect on the relatively large area of the wall 34, and

the movable contact 36 carried by the cylinder is urged into engagement with its assoclated contact 39 against the actlon of the coiled sprlng 37.

' When one of the alternating currents energizing the magnet is of the frequency to which the reed is attuned, the corresponding pulsations of magnetic attraction will be in synchronism with the natural elastic swings of the reed and will build up wide vibrations of the reed whereby its slotted end is oscillated back and forth before the air jet nozzle. Thus the jet stream will be broken up and most of the air which before passed unimpededthrough the slot in the reed, will now impinge against the body portion thereof. The slot and the jet being both very thin in the direction of vibration of the slot, a

correspondingly small vibration of the reed vvill cut off the jet; or a wide vibration will cut it off for a greater fraction of the total swing. The pressure of air passing through the piston and acting in the cylinder will thus be greatly reduced so that leakage be tween cylinder and piston and etllux through orifice 82 will permit coiled spring 37 to become active to telescope the cylinder 34 over the piston 33 and withdraw the movable contact 36 to open the relay circuit.

A coiled tension spring 50 connected to the free end oftlie reed and to a rotatable adjusting pin 51 is primarily intended'for adjusting the slot for accurate registry with the nozzle, but it could be used for deflecting the reed to a position where the jet would be normally baffled and would act effectively on the piston only when the end was vibrated to bring the slot 27 into alignment with nozzle 28 and intake 32. In such case, the circuit would be closed instead of broken when the reed vibrates. The latter result ismore effectively attained by making the free end of the reed as shown in Fig. 8 wherein there is a tongue 27 taking the place of the slot 27 The magnets will of course be energized by various currents passing to other similar but differently tuned instruments on the same line but such currents as are not of iroper frequency will be inoperative to vibrate the reed with the amplitude necessary to substantially affect the jet for the proper transmission of signals through the relay circuit. i

Lead wires (not shown) to the relay circuit and to the carrier line may be attached to suitable binding .posts 52 52, 52", 52, mounted in plates 53 of insulating material secured upon the frame plate 13" and serving to insulate the binding posts from the frame plate. Leads 54 from the binding posts ,52, 52 go to the .two coils of the electromagnet and the leads 55 from the binding posts 52, 52 of the relay circuit connect with the stationary and movable contacts 86, 39 respectively. These contacts are insulated from each other by suitable spacer blocks 56, 57 of insulating material. If desired, the movable contact may be grounded and connected through the frame to a binding post.

The various adjustments of the relay which cooperatively serve to make it a hi ghly refined and sensitive instrument may be briefly re-enume ated as follows:

The force of the air blast may, of course, be regulated in any appropriate manner (not shown). The frequency of vibration of the reedis determined by proper selection of the size of the weight 19. The extent of the vibratory sway of the reed may be adjustably regulated by the angular spring arm 42. Adjustment of the weight 49 on the damping rod 47 may be so regulated that the reed may be quickly damped when current is out off without having the damping means interfere with the normal reed vibration.

tively stationary contact member 89. For accurately positioning the reed so that when in normal rest position the slot 27 will register with the air jet nozzle, I employ the adjusting pin5l and tension spring 50. By adjusting this tension the continuous pull exerted by the polarized magnet may be ac curately counterbalanced and the slot properly located even though the magnet be adj usted nearer to or farther from the reed armature.

In Fig. 9 I have indicated one way in which my transmitter and receiver at one station may be connected in on the circuit of a bridge quadruplex telegraph line without interferi with the regular quadruplex operation and without having my sending instrument operate its companion receiving instrument at the same station. In this figure the regular line conductor 70, terminates in the usual split impedance coils 71, 71, which are wound upon the same core and which are opposed and their impedance neutralized with reference to current entering through middle wire 7 3 but are of high impedance to currents from and 70 The terminal 70 is grounded through an artificial line 7a, which has the same resistance and capacity as the real line 70. The middle wire 73 connects with the usual bridge quadrupleX sending instruments and grounds which are of well known types.

Omitt-ing for the moment consideration of the details of my transmitter and assuming current in the secondary 75 of my sending circuit, one end of this secondary is connected to ground 76 and the other end through wire 77, to the middle point of split condenser 79, 7 9, in bridge 80 across the line between line conductor 70 and the artificial line 74.

he receiving instrument is diagrammatically indicated as connected in a parallel bridge 81, serially including condenser 82 and the windings 23 of the receiving electromagnet.

It will be seen that alternating current originating in secondary 75 and applied at the middle point of the split condenser 79, divides equally and flows half to real line 70 and half to the artificial line 74. At the junctions of the bridge 80 with sa'l line wires the current again tends to split, half seeking to flow through the split impedance 71, 71, but being prevented because of the.

direction in which those said iinpedances are wound. The parts of the current that tend to flow from the junction points, away from the impedance coils are equal and opposite upon the terminals of the bridge circuit 81 and therefore neutralized and produce no current in said bridge. The half current from the lower end of bridge 80 has a flow path through the artificial line 74, and thence through. ground 7 6 to the other terminal of its source, which is the secondary 75. This leaves a desired fraction of the current on the line which will travel to-thc distant station where there will cause no condition of balance on the distant bridge 81, but entering the upper end of that bridge will flow through the receiving magnet 23 therein and thence out through the artificial line to its ground 7 l. 7

The relay circuit energized by a battery 87 and controlled by the pneumatic make and break mechanism above described, serves to operate a printing key, a sounding mechanism or any other desired fi glfill'atilfl. For purposes of illustration 1: have shown a sounding apparatus 88 in tl e relay circuit.

if we suppose the frequency originating in secondary 76,.is 60 cycles, it is obvious that a precisely similar sending and receiving apparatus operating at 120 cycles, may be similarly bridged on the line at the same station without the possibility of one interfering with the other. The number of such parallel sets of instrun'ients at each end of the line is limited by the number of frequencies that it is practical to use. Practical limits are that the frequencies should be not too high, or too low, or too close to each other.

In Fig. 9 the sending current is shown as energized from a direct current generator 67, the circuit being manually made or broken through the medium of a conventional telegraph switch key 60. A circuit interrupter for impressing a pulsating current on the primary coil 61 of the sending circuit is indicated as comprising a magnet winding 62 energized when the key 60 is closed and an armature 68 attracted by the magnet and mounted on a vibrating reed 69, accurately tuned to the frequency of the desired current. As the armature is attracted by the magnet 62, the circuit is broken by a contact on the reed as indicated at 64. The armature is then retracted by resilience of the reed which will execute its vibratory swings at the rate for which it is tuned, the circuit make and break being continuously repeated at the frequency determined by the elastic swing of the reed, as long as the switch key is held downv The usual condenser 66 is employed across the points of the circuit interupter. Other types of interrupters or alternating current generators might be utilized provided that they were properly governed to impress currents of the correct frequency on the sending circuit. I find, however, that by using a reed. as the vibrating circuit breaking member of the in terrupter and employing an adjusting weight 68 on the free end of the reed, the in terrupter may be more accurately tuned in order to produce the desired exact frequency for the pulsating current.

It will be understood that the receiving reed 27 is in practice a spring strip usually I block In .tliCSc two wayg cut from metal, usually brass or other nonmagnetic material. This metal is preferably thin so that the reed will not be too stifi and, in the form shown in the drawings, the portion of the reed between the armature and the slotted upper end is reeni'orced by stiffening strip X. The weight of this strip must 01" course be reckoned as part of the weight determining the natural frequency of vibration of the spring Such stiii'ening strip tends to prevent whipping or complex vibration of the upper end oi the reed and localizes the resilient bending action at the lower end of the reed adjacent the clamping the stiffening strip tends to make the reed more pendulumlike and single-trequency in its vibration.

In applying my invention to an instrumentconstructed substantially as herein shown and described, I have found it desirable to have the jet orifice at 28 very narrow, the

slot- 27 slightly wider and quite close to the jet orifice and the intake opening still wider. Also it is very desirable to have the jet outlet at 28 as narrow as practicable, so that when the reed is stationary very narrow slot 27; will permit tree passage of the jet. The thinner the jet and the narrower the slot in the reed, the less vibration is necessary to completely bafile the jet. The required power may be had; from a very thin jet if it is made long enough. In the device above. referred to, the jet outlet was about 1/64? wide X 14/64, but it is obvious that the principle of my invention may be employed in connection with almost any shape, size and power of jet, suitable to special purposes other than tuned reeds and; other than multiplex telegraphy.

I claim:

l. A receiving instrument including means for continuously maintaining an air jet of approximately uniform volume and velocity, motor means actuated by the jet, a vibratory member adapted to vibrate across the path of the j st to variably battle the same and control the effect thereof on the motor means and signal means actuated by the motor means.

2. A receiving instrument including means for maintaining an air jet, motor means actuated by the jet, signal means under control of the motor means and a vibratory member movable across the path of the jet to bafile the same, and regulate the efiect o f the jet on the motor means 3. A receiving instrument including means for producing an air jet, an element movable transversely in the path of the jet to battle the same, electromagnetic means whereby sail element may be caused to move or remain stationary, motor means controlled by the.

jet and an indicating device operable through the medium of; the motor means.

4:. A receiving instrument including means for continuously maintaining an air jet, a movable element actuated by the jet, a tuned reed having its path of vibration intersecting the path of the jet passage and arranged to normally permit substantially free passage of the jet and when vibrating to battle the jet, and indicating apparatus controlled by the movable member.

5. A receiving instrument including means for continuously maintaining an airy jet, a movable element actuated by the jet, a tuned reed having its path of vibration intersects ing the path of the ct passage and arranged to normally permit substantially free pas-v sage'of the jet and when vibrating to battle the jet, and indicating apparatus controlled by the movable member, together with an electromagnet for vibrating the reed and; means for causing relatively feeble fluctuations in the magnet of the same frequency to which the reed is tuned. V

' 6. A receiving instrument including means for continuously maintaining an air jet, a reed adapted to be vibrated across the path of the jet to variably battle the same, a mov able member under control of the jet and contact making mechanism for a relay circuit controlled by the movable member.

7. A receiving instrument including a tuned reed having a slotted end, means for directing an air jet against the slottedv end of the reed, means controlled by the jet passing through the reed for operating a relay circuit, and electromagnetic means for vibrating the reed to bafiie the jet.

8. A receiving instrument including a tuned reed having a slotted end, means for directing an air et against the slotted end of the reed, means controlled by the jet passage through the reed for operating a relay circuit, and electromagnetic means for vibrating the reed to baflie the jet, said electromagnetic means comprising an electromagnet energized by feeble magnetic fluctuations oi the frequency to which the reed is tuned.

9, A receiving instrument,including means for maintaining an air jet, a vibratory member movable across the path of the jet to variably baffle the same, contact making mechanism for a relay circuit controlled by the jet after it has passed beyond the path of movement of said member.

10. A receiving instrument. including means for maintaining an air jet, a vibratory member movable across the path of the jet to variably battle the. same contact making mechanism for a relay'circuit controlled by the jet after it has passed beyond the path of movement of said member, and means for electromagnetically vibrating said member.

l1. Means tor controllinga relay circuit comprising a stationary contact, a movable contact, a movable cylinder forv actuating said contact, stationary piston over which the cylinderis loosely fitted, means for con tinuously maintaining an air jet and for discharging the air jet through the piston to exert pressure on the cylinder and means for interfering with the normal flow of the jet.

12. Means for controlling a relay circuit comprising a stationary contact, a movable contact, a movable cylinder for actuating said contact, a stationary piston over which the cylinder is loosely titted, means for continuously maintaining an air jet and for dis charging the air jet through the piston to exert pressure on the cylinder and means for interfering with the normal flow of the jet, said means comprising a vibrating reed moving between the discharge nozzle of the jet and the piston in a path transverse to the flow of the jet.

13. Means for controlling a relay circuit comprising a stationary contact, a movable contact, a movable cylinder for actuating said contact, a stationary piston over which the cylinder is loosely titted, means for con tinuously maintaining an air jet and for discharging the air jetthrough the piston to exert pressure on the cylinder and means for interfering with the normal fiow of the jet, said means comprising a slotted vibratory member operable to battle the jet or to permit free passage thereof to the piston.

14:. An electrical relay including a magnet,

a reed vibrating in synchronism with the frequency of the current in the magnet, an armature for the magnet carried by the reed, said reed having a slot therein, means for directing an air blast against the slotted portion of the reed, and contact making mechanism for the relay circuit controlled by the blast passing through the slotted portion of the reed.

15. An electrical relay including a magnet,

a reed vibrating in synchronism with the frequency of the current in the magnet, an armature for the magnet carried by the reed, said reed having a slot therein, means for directing an air blast against the slotted portion of the reed, contact making mechanism for the relay circuit controlled by the blast passing through the slotted portion of the reed, and means for adjusting the reed to normally ba-iile or normally admit air to the contact making mechanism whereby the con- .acts may be selectively opened or closed upon vibration of the reed under the influence of the magnet.

16. An electrical relay including a magnet, a reed vibrating in synchronism with the frequency of the current in the magnet, an armature for the magnet carried by the reed, said reed having a slot therein, means for directing an air blast against the slotted portion of the reed, contact making mech anism for the relay circuit controlled by the blast passing through the slotted portion of the reed, and means for damping vibration armature for the magnet carried by the rest said reed having a slot therein, means for directin an air blast against the slotted portion of the reed contact makin mechanism for the relay circuit controlled by the blast passing through the slotted portion of the reed, said reed carrying a weight proportioned to properly time its vibration.

18. An electrical relay including a magnet, V

a reed vibrating in synchronism with the frequency of the current in the magnet, an armature for the magnet carried by the reed, said reed having a slot therein, means for directing an air blast against the slotted portien of the reed, contact making mechanism for the relay circuit controlled by the blast passing through the slotted portion of the reed, and means for limiting the vibratory sway of the reed.

19. An electrical relay including a slotted reed, means sensitive to an incoming electrical current of predetermined frequency for vibrating the reed, means for directing an air blast against the slotted portion of the reed, and a contact making member for the relay circuit movable under the influence of the blast to control said circuit.

20. In a relay, an electrically operated vibrating reed having an opening therein,

means for directing an air blast against the reed adjacent the opening whereby the opening will control the blast passing through the reed, telescoping piston and cylinder members normally spring urged into telescoped position, one of said members being movable under the influence of the blast passing through the reed and contact making mechanism for the relay circuit controlled. by such movable member.

21. In a relay, an electrically operated vibrating reed having an opening therein, means for directing an air blast against the reed adjacent the opening whereby the opening will control the blast passing through the reed, telescoping piston and cylinder members normally spring urged into telescoped position, one of said members being movable under the influence of the blast passing through the reed, contact making mecha' nism for the relay circuit controlled by such movable member, and means for predetermining the throw of the movable member necessary to close or open the contacts.

22. A relay including an electrically vibrated slotted reed, an air blast nozzle discharging adjacent the slotted portion of the reed, a telescoping piston and cylinder having an opening therein in alignment with the nozzle and adapted to be relatively moved by the blast passing through 1 the luv slotted portion of the reed, means yield;

slotted portion of the reed, means yieldmgly opposing such relative movement of the piston and cylinderunder the influence ot' the air blast, contactmaking mechanism controlled by such movement and means for normally retaining the slotted portion of the reed either in or out of alignment with the nozzleand the inlet whereby the movable member may be held in either one or the other of its extreme positions when the reed is vibrated. v

24. An electrical relay including a polarized electromagnet by alternating electric current, a reed energized by said magnet and vibrating in synchronism with the cycles of the current that energizes the magnet, an armature for the magnet mounted on the reed, and pneumatic contact making apparatus for the relay controlled by the reed. v I

A relay oi the class described, including an electrically operated vibrating reed having a slot therein, an air blast nozzle discharging adjacent the slot, a stationary piston member having an inlet in alignment with the nozzle, a cylinder member telescoping on the piston, and movable under the infiuence of the air blast, means yieldingly opposing such movement of the cylinder, and contact making apparatus including a relatively movable contact rigidly connected to the cylinder.

26. An electrical relay including an electrically vibrated reed having a slot therein, pneumatic contact making apparatus for the relay circuit including means for directing an air blast against the slotted portion of the reed and means for varying the cti'ectiveness ot the blast including an adjusting member for selectively holding the reed either normally in or normally out of blast battling position.

2. An electrical relay including an electrically vibrated slotted reed, pneumatic contact making apparatus controlled by the reed, means for damping the movement of the reed including a damping rod passing freely through an opening in the reed, and means pressing the rod against the wall 01" such opening. 7 1

28. An electrical relay, including an electrically vibrated reed, relay circuit making apparatus pneumatically controlled by the reed, means for'limiting the vibratory sway of'the reed including a spring arm adapted for disposition closely adjacent the reed and means for adjusting the arm to vary its distance from the reed.

29. An electrical relay including a reed clamped at one end and including an enlarged weighted portion, an armature car- 'ried by the enlarged portion of the reed,

polarized electromagnet cooperating with the armature to produce vibration of the reed, said reed having a slot' in its free end and pneumatic contact making apparatus controlled by the slotted end of the reed.

A device of the character described in claim 29 and wherein the slotted portion of the reed is coaxial with and disposed in a plane at right angles to the body of the reed.

31. A receiving instrument including a nozzle having an orifice for discharging a substantially flat airjet, a vibrating reed including a free end vibrating in a path at ri ht angles to the air jet and having a slot therein normally in alignment with the air jet, means controlled by the jet pass through the slot in the reed for operatii signal mechanism and means for vibrating the reed to bathe the jet.

32. A receiving instrument including a flat nozzle for discharging a substantially flat air et, a vibrating reed including a free end vibrating in a path at right angles to the air jet and having a slot therein normally in alignment with the air jet, means controlled by the jet passing through the slot in the reed for operating signal mechanism and means for vibrating the reed to batlie the jet, said slot in the .reed being sufliciently elongated to permit the passage of an operative air current and sufficiently narrow to eflect bafiling by a relatively slight vibration.

33. A receiving instrumentincluding means for maintaining an air jet, a stationary concave piston into which said jet normally discharges, a relatively light movable cylinder telescoping loosely on the piston and provlding an annular vent around the piston, means yieldingly opposing the movement ofthe cylinder under the influence of the air jet, signal operating mechanism controlled by the pistonand means for battling the air blast to render the cylinder inoperative. v

34. A receiving instrument including means for maintaining an air jet, a stationary concave piston into which said jet normally discharges a relatively light movable cylinder telescoping loosely on the piston and providing an annular vent around the piston, means yieldingly opposing the movement of the piston under the influence of the air jet, signal operating mechanism controlled by the piston and means for bathing the air blast to render the cylinder inoperative, said last mentioned means comprising a vibrating reed having a slot therein, disposed in alignment with the jet when the reed is at rest.

35. A receiving instrument including means for continuously maintaining an air jet of approximately unitorm volume and velocity, motor means actuated by the jet and a movable contact carried by the motor means, a vibratory member oscillatable across the path of the jet to variably battle the same, a relatively stationary contact cooperating with the movable contact and adjustable to predetemine the force which must be applied to the motor means to effect closing of the contacts.

36. A. receiving instrument including a vibratin reed, a su mortsi 'nal. anaratus pneumatically controlled by the reed, an electromagnet, an. armature on the reed controlled by the magnet, means for varying the distance between the magnet and the armature including a spring bracket mounting for the magnet rigidly lined at one end to the support and means passing through the support and acting against the free end of the spring bracket to bodily move the.

bracket. 7

51A receiving instrument including means for continuously maintaining an air jet of approximately uniform volume and velocity, motor means actuated by the jet, signal mechanism controlled by the motor means, a vibrating reed having a slot therein cooperating with the jet to pneumatically control the motor means, said slot being disposed in the portion of the reed having the greatest movement when the reed is vibrated.

38. A receiving instrument including a nozzle from which an air jet is discharged, a vibrating reed having a slot therein, motor means having an air intake in alignment with the nozzle and means for adjusting the reed to align the slot therein with the nozzle. i

39. A receiving instrument including a nozzle from which an air jet is discharged, a vibrating reed having a slot therein, motor means ha ing an air intake in alignment with the nozzle and means for adjusting the reed to align the slot therein with the nozzle, said last mentioned means comprising a tension spring and a rotatable adjusting pin for exerting tension on the spring.

ii). A receiving instrument including a nozzle adapted to discharge an air jet, means operated by the jet for controlling signal mechanism, a vibrating reed including a slotted portion disposed at right angles to the body of the reed and adapted to vibrate in a plane transverse to the plane of the air jet to battle the same.

ll. [is a new article of manufacture, a reed of the class described including a body portion and a slotted free end disposed at right angles to the plane of the body portion and adapted to vibrate in such plane.

Signed at Chicago, in the county of Cook, and State of Illinois, this 18th day of August, A. D. 192 i.

. RAY EDWVIN HALL. 

